The base PS4 has 8 GB of RAM, and it doesn't have to keep Windows in memory along with the games. 16 GB will ensure the PC will be useful for a few years to come. Really, you probably want more RAM and CPU than you need, so that you can continue to use the PC for years only having to swap out a new video card. AMD's latest CPUs are certainly good enough and affordable, so maybe give one of those a try.

Any modern system is reserving RAM for the OS. A base PS4 has 4.5 or 5GB of the total 8GB available for games, depending on how you want to count it. The OS also reserves two of the CPU cores. Similar things are the case for the XB1, and the Switch reserves basically 1/4 of its resources for the OS (1 of 4 CPU cores, and 1GB of 4GB total RAM). On top of that, you're looking at shared memory for all the consoles, so a lot of that is likely being used as VRAM.

I still would tend to go with more RAM in a PC to futureproof, but it's likely not being utilized by gaming unless you're setting up a virtual disk swap or something. Also, figure, RAM was cheap for a while, and likely will be again. It wasn't so long ago that you'd throw 16GB in over 8 because it was maybe an extra $30-40 so why not? 8GB is currently quite fine though, and at today's prices would be better left as a future upgrade (if possible).

Windows doesn't use multiple gigabytes of memory all on its own, and I'd assume that the console OSes don't either. Keeping in mind that 32-bit Windows 10 will run on machines with 1GB total memory, where 64-bit specs 2GB. They may run relatively poorly, but they can function.

Instead, it's more a matter multitasking (or background processes), or how much can be cached for quick access. The bigger difference is more that Windows won't be like, okay, these first 3GB are for me, and Skype, and Edge, and Windows Update, and Xbox, and Media Player, etc...and the rest is yours and is instead keeping all resources on the table. Consoles are just still more the managed experience. They're setting a chunk of resources and restricting how applications can be run (closing one game if you open another for instance) to ensure that everything works.Windows, sure, you have the ability to overload the system with all sorts of agents and apps and all that and the OS will do its best. That doesn't mean Windows itself is a massive RAM hog.

I haven't kept up on RAM prices. When I got my machine it can max out at 32 and that seemed well into overkill. Knowing that Windows 8/10 would use 2GB just to sputter by with on its own I was thinking about future proofing with an opening on the back end for even more later (same with the CPU as I middled out on the i7.)

That's why when I look at a PC (desktop/laptop) I try and budget and design around a good total cap vs starting out RAM base vs also how many slots exist to make the deal most sensible. Sometimes a pair of 4GB can look nice to hit 8, but when you have 4 slots and you want to go up to X suddenly you may have to retire what's there buying 4 sticks instead of 2 at worse of a cost. Video cards basically are whatever, if it fits in the slot and won't require going with an even beefier wattage power supply you're fine lowballing and growing later. Same can be said relatively so with the CPU as long as that solid motherboard has the room later for nicer things too. Cost vs benefit now and say 3-5yr later too vs total replacement. When you can baby step more buys later to add solid life with a quality boost it's great.

Naw, bro, always install your memory in pairs these days. Almost every single PC out there now supports dual-channel memory, and while I can't speak to whether the difference is noticeable, it's worth getting adequate RAM out the gate and making sure you use two matched DIMMs to get dual-channel performance. Besides, once a memory technology becomes a bit antiquated prices start to go up and up and up. So boosting memory on an older machine can actually be more expensive than buying the memory you anticipate needing in the future right out the gate. Safest way to play this with a desktop is to get a system with 4 slots, and put 8 or 16 total (I recommend 16) in your system with paired 4 or 8 GB DIMMs. And if you need more memory down the road you have 2 slots free and can buy another pair of DIMMs to throw in. You probably do not want to patch your machine along a single DIMM at a time. That's a pain.

In truth, I always try to build my PCs with more than adequate CPU power, more than adequate RAM, and a larger power supply than I anticipate needing. You should only really plan on upgrading or replacing stuff like hard drives, RAM (probably only 1 time, max), and video cards, and having everything else be more than you need is the way to go. It minimizes the amount of time you spend with your system open on the floor and ensures your upgrades won't be overly complicated.

Ideally, yeah, use dual channel (or triple/quad if workstation hardware). It's a pretty nice performance bump for a lot of tasks. That said, for gaming it tends to be a relatively small difference (a few FPS or so) if you're using a discrete card. On the other hand, RAM performance (dual channel in particular) tends to provide a major increase to integrated graphics (for some examples).

You know, I'm going to take a guess that games that are optimized for multiple cores will see bigger boosts from multi-channel memory, because those cores have to communicate. Multi-core activity involves more and more frequent memory accesses.

I was thinking like let's say you have 4 memory slots. You want to upgrade, but think future too.

My system takes 32GB max, so I have a pair of 8GBs in there. I only wanted 16 at the time and got this, but I could have been stupid and bought 4x4GB sticks which would have cost at that moment in time a little bit less. I was thinking long term. I know buying dual sticks and dual channel memory are a thing, have been for quite a long time too.

I would would imagine that guess about dual core vs dual channel memory probably does work as a plus towards that.

The only path I took different was the moderate i7 chip because 3 years ago the beefiest option which was $980 then the Intel Extreme Edition i7-4940MX that runs base at 3.1ghz and turbo's in games(etc) to 4ghz (and 8MB cache). My current processor is much the same on that G3 Haswell design, but is 2.5ghz and taps out turbo at 3.5ghz (w/6MB cache). That would be a significant improvement at +500mhz and +2MB in the cache but wasn't worth $1K to me at the time.